Heater vacuum diagram,anybody?

[K5Steve]

I have an 88 blazer with a/c.All my air comes out of the dash vents and the floor,no def.I know it is vacuum operated but can't find where the line are supposed to be hooked up to.My temp controler also doesn't slide all the way to cool,about an inch away from the far left side,so I'm not getting it all the way over to hot either.I know the heater core isn't clogged.Could the vacuum run that too?I did a search but couldn't find one for my truck.Thank you.

 

[HarryH3]

You might have to cut-n-paste this link into a new browser window to get it to work, but the diagram is posted here:

http://www.angelfire.com/super/ThunderTruck/images/VacDiagram.gif

 

[K5Steve]

Doesn't work either way.

 

[HarryH3]

'cause the freakin' stupid software insists on shortening the real link and stuffing those "..." characters in it. Try pasting this link (and adding in the "www" at the beginning of the string):

.angelfire.com/super/ThunderTruck/images/VacDiagram.gif

 

[K5Steve]

Bada bing!Thank you!

 

[shane74]

It's probably not the vacuum system that is broken. There is a little plastic tab that connects to the linkage arm off the vacuum modulator. It is held on with a screw and mounted on a hinged door INSIDE the heater box behind the glove box. You have to pretty much pull it all apart to get to it. It's a $3 part that is known for breaking. YOu'll know it whe you see it. I bet if you replace that part, all your air flow problems are solved.

BTW, I had the EXACT same problem in every chevy truck/blazer/suburban I have ever owned. It has always been that little plastic tab. I'm pretty quick at replacing them now!

 

[K5Steve]

How does the cool/hot lever work?Vacuum or cable?

 

[K5Steve]

Is it an easy fix?I'll pull the glove box out tonight.

 

[K5Steve]

Ok,I got the glove box out and the plastic pieces are good,I can move the selecter door to the position I need but not all the way on defrost.It looks like I have to adjust it,there is a threaded piece to adjust.My vaccum line looks good but I lose it once it goes into the firewall.It looks like it goes into the cowl(wiper area) then that's where I lose it.I can't find the same wire once in the engine bay.I may just run a new line.